Technical Field
The disclosure is related to display technology field, and more particular to a thin film transistor array substrate and a manufacturing method thereof being able to prevent the threshold voltage (Vth) from drifting in a case of the negative bias illumination stress (NBIS).
Related Art
With the evolution of optical and semiconductor technology, the flat panel display has been flourishing. Among the various flat panel displays, the liquid crystal display (abbreviated LCD) has become the mainstream on the market due to due to the various superior characteristics such as the high space utilization efficiency, low power consumption, no radiation and low electromagnetic interference.
The liquid crystal display device usually comprises a liquid crystal display panel and a backlight module arranged opposite to each other. The backlight module provides display light to the liquid crystal display panel. The liquid crystal display panel usually comprises a thin film transistor array substrate, a color filter substrate, and a liquid crystal layer sandwiched between these two substrates. The image display is achieved by applying voltages to these two substrates to further control the rotation of the liquid crystal molecules in the liquid crystal layer to achieve light passing or not passing.
The thin film transistor array substrate comprises various thin film transistors formed in an array on a substrate. Compared with the conventional a-Si thin film transistors, the a-IGZO thin film transistors have the advantages of higher electron mobility, low preparation capabilities, excellent preparation of large area uniformity, good transparency for visible light, higher on/off ratio and low threshold voltage (Vth). The a-IGZO TFT becomes the preferable switching element for the active matrix display in recent years. However, under the situation of negative bias illumination stress (NBIS), the threshold voltage of the a-IGZO TFT is easily to drift. Therefore it is difficult for the a-IGZO TFT to achieve large-scale production.